Bin-bin Zhang, Y. Ma, Guanji Lyu, Shikang Wu, Hui-Ning Jiang, Yantong Hu, Tao Ji
{"title":"Sulfate resistance of ultra-high performance concrete with recycled fine aggregate","authors":"Bin-bin Zhang, Y. Ma, Guanji Lyu, Shikang Wu, Hui-Ning Jiang, Yantong Hu, Tao Ji","doi":"10.1680/jadcr.21.00187","DOIUrl":"https://doi.org/10.1680/jadcr.21.00187","url":null,"abstract":"The effect of sulfate attack (SA) on the strength of ultra-high performance concrete (UHPC) with recycled fine aggregate (RFA) is investigated. RFA is used to replace natural fine aggregate (NFA) at 0%, 50% and 100% by weight. UHPC samples are soaked in 10% sodium sulfate solution for 0–180 d (SA age). The sulfate ion concentration, flexural strength and compressive strength of UHPC are investigated. The microstructure of UHPC before and after SA is analysed through a multi-technique approach (ITZ, XRD, SEM-EDS and MIP). Results indicate that with the increase of SA age, the compressive strength of UHPC with RFA increases. The generated gypsum and ettringite refine the harmful pores (>20 nm), which is converted to harmless pores (<20 nm) in UHPC matrix. At the same SA age, the sulfate ion concentration of UHPC increases with the increase of RFA content due to more ITZ, pores and microcracks introduced by RFA. The strength development models of UHPC with different RFA content under SA are developed.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42278609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Çelik, Oguzhan Yildiz, A. B. Çolak, Samet Mufit Bozkır
{"title":"Analyzing of Nano-SiO2 Usage with Fly Ash for Grouts with Artificial Neural Network Models","authors":"F. Çelik, Oguzhan Yildiz, A. B. Çolak, Samet Mufit Bozkır","doi":"10.1680/jadcr.21.00180","DOIUrl":"https://doi.org/10.1680/jadcr.21.00180","url":null,"abstract":"During grout penetrating to voids and cracks in soils and rock layers, pumping grouts easily and effectively is vital parameter for especially grouting works in geotechnical improvements. For this reason, improving the rheological parameters of cement-based grouts and increasing the fluidity are important for an effective grouting injection. In this study how nano silica (n-SiO2) together with fly ash will affect the rheological behavior of cement-based grouts has been experimentally investigated and analyzed with artificial neural network (ANN) models. The effects of nano silica (n-SiO2) additions at different contents by mass (%0.0, %0.3, %0.6, %0.9, %1.2 and %1.5) on plastic viscosity and yield stress values of cement-based grouts incorporated with fly ash as mineral additive at different constitutes (%0-for control purpose, %5, %10, %15, %20, %25 and %30) were investigated in this study. Moreover, using the obtained experimental data, a feed-forward (FF) back-propagation (BP) multi-layer perceptron (MLP) artificial neural network (ANN) has been developed to predict the plastic viscosity and yield stress of cement-based grouts with n-SiO2 nanoparticle additives. The developed ANN model can predict the plastic viscosity and yield stress values of cement-based grouts containing n-SiO2 nanoparticle doped fly ash with high accuracy.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44775507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. McCarter, B. Suryanto, Hussameldin Mohamed Taha Abdalgadir, G. Starrs, Jaehwan Kim
{"title":"Features of Immittance Spectra as Performance Indicators for Cement-Based Concretes","authors":"W. McCarter, B. Suryanto, Hussameldin Mohamed Taha Abdalgadir, G. Starrs, Jaehwan Kim","doi":"10.1680/jadcr.22.00023","DOIUrl":"https://doi.org/10.1680/jadcr.22.00023","url":null,"abstract":"The design for durability and performance-based standards and specifications for reinforced concrete infrastructure, is limited by the lack of rapid, science-based test methods for characterizing the deterioration resistance of concrete. In this paper, this issue is addressed though the application of two-point electrical impedance measurements taken within the frequency range 100Hz-10MHz. Data are presented for a range of industry-standard cement-based concrete mixes with and without supplementary cementitious materials (SCM's). The Nyquist (-iZ’’(ω) vs Z’(ω) and Bode (Z*(ω) and θ vs frequency) formats clearly highlight the frequency dependence of the electrical response, however, when presented in the form of permittivity and conductivity, a region of dispersion was evident over the entire frequency range for all concretes. Features of this response, which could be gainfully exploited as durability indices for assessing the long-term performance of concrete, are identified and discussed. A range of formalisms is presented, and it is shown that within this frequency range the conductivity was found to obey Jonscher's universal power-law. Two novel durability parameters are presented based on features of Jonscher's model and, from a practical viewpoint, the power-law model can be evaluated using conductivity measurements obtained at three, easily measured, spot frequencies (viz. 10kHz, 1MHz and 10MHz).","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47095401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Shrinkage of High Strength Engineered Cementitious Composite with Zeolite Particles as Internal Curing Agent","authors":"Qing Wang, Wenjie Huang, Jing Sun, Jun Zhang","doi":"10.1680/jadcr.19.00143","DOIUrl":"https://doi.org/10.1680/jadcr.19.00143","url":null,"abstract":"In this paper, shrinkage and internal relative humidity of internally cured ordinary Portland cement-based high strength engineered cementitious composite (OPC-HSECC) are experimentally investigated. Natural zeolite and calcined zeolite particles were used as internal curing agents. Calcination and substitution ratio of internal curing admixture that affects the shrinkage reduction efficiency of HSECC were inspected in the tests. Meanwhile, the effects on compressive strength of the composites are inspected. Test results show that development of shrinkage and internal relative humidity of OPC-HSECC exhibits two-stage progressing mode. As for shrinkage reduction efficiency, pre-wetted calcined zeolite particles is higher than that of natural zeolite in OPC-based cementitious composite and total shrinkage is reduced by more than 54% at 28 days, on the condition that the compressive strength is similar with the reference. According to the results, the optimized replacement ratio of calcined zeolite is around 30%.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47198478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Contribution of turbidimetry on the characterization of cement pastes bleeding","authors":"Y. El Bitouri, N. Azéma","doi":"10.1680/jadcr.22.00040","DOIUrl":"https://doi.org/10.1680/jadcr.22.00040","url":null,"abstract":"The aim of this paper is to examine the contribution of turbidimetry measurements on the characterization of cement pastes bleeding. In some cases (e.g. presence of superplasticizer), the bleed water becomes turbid due to finest particles dispersion and the boundary between the bleed water and the consolidated paste becomes difficult to detect. Turbiscan device allows detecting this boundary more accurately than traditional tests. The role of superplasticizer and solid volume fraction on bleeding is examined. The bleeding measurements highlight the role of superplasticizer on bleeding and its kinetics. The effect of superplasticizer may be explained by better dispersion leading to release of water trapped between agglomerates. Furthermore, the existence of critical volume fraction, above which no bleeding occurs, close to that corresponding to the appearance of contacts between particles is shown. Finally, using rheological measurements, the correlation between the yield stress and bleeding has been possible.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47133352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Utilization of Low Reactivity Fly Ash for Fabricating Geopolymer Materials","authors":"A. Poowancum, Prasert Aengchuan","doi":"10.1680/jadcr.21.00025","DOIUrl":"https://doi.org/10.1680/jadcr.21.00025","url":null,"abstract":"Low reactivity fly ash (LRFA) is obtained from a low temperature combustion furnace, is a low-pozzolanic activity ash, is a hazardous waste, and is undesirable for engineering applications. The aim of this work is to investigate the mixing procedure for fabricating a cement replacement material, i.e., geopolymer by using LRFA blended with the calcined kaolinite clay as a precursor. A mixture of sodium hydroxide and sodium silicate is used as an alkaline solution. The results show that to obtain sufficient strength for engineering applications, the sequence mixing (SM) procedure is required. Using the conventional mixing method, geopolymer has high porosity and low strength. Because the gas bubbles are generated from the reaction between alkaline solution and the impurity in LRFA during the hardening process. By using the SM method, the generated gas bubbles are released before the geopolymer is hardened. As a result, the porosity is reduced, and the strength is significantly increased. The 7-day strength of geopolymer fabricated by the SM method is higher than the minimum requirement of Portland cement. In addition, the SM procedure reduces the setting time of LRFA-geopolymer, which is an advantage for rapid repair applications.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44705981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Deng Chen, L. Mo, A. Wang, Kaiwei Liu, Shiping Zhang, Tao Yang
{"title":"The hydration, strength and deformation of Portland composite cements containing light-burnt dolomite and metakaolin","authors":"Deng Chen, L. Mo, A. Wang, Kaiwei Liu, Shiping Zhang, Tao Yang","doi":"10.1680/jadcr.21.00141","DOIUrl":"https://doi.org/10.1680/jadcr.21.00141","url":null,"abstract":"Light-burnt dolomite (LBD) as a compound MgO expansive agent can compensate effectively the shrinkage of concrete at early ages. However, in terms of strength, the replacement amount of Portland cement with LBD is limited due to the low reactivity of calcite in LBD. In this study, metakaolin used as a modified material was incorporated into the blended cements containing LBD to improve the reactivity of calcite in LBD. The results showed that the incorporation of LBD and metakaolin decreased the hydration heat and strengths of Portland cement at early ages, but the strength increased with increasing the mass ratio of metakaolin to LBD at later ages. Especially, the strengths of the blended cement containing 20% metakaolin and 20% LBD were even higher than those of Portland cement. This was mainly related to the formation of compact pore structure with decreased porosities due to the improvement of the reactivity of calcite in LBD and the pozzolanic reactivity of metakaolin. Additionally, in comparison to Portland cement, the incorporation of LBD and metakaolin could produce a certain expansion due to the high hydration reactivity of MgO in LBD, and mitigated the shrinkage.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47982605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Investigating the physical and chemical contribution of ground low-quality fly ash particles to cementitious composites","authors":"Meenakshi Sharma, Rohit Bhushan, Satya Medapalli, Shashank Bishnoi","doi":"10.1680/jadcr.21.00173","DOIUrl":"https://doi.org/10.1680/jadcr.21.00173","url":null,"abstract":"This work investigates grinding as a potential solution to improve the utilization of low-quality fly ashes in concrete. Factors contributing to the performance of ground fly ash in cementitious composites were investigated. Grinding significantly crushes large cenospheres particles and increases specific gravity and surface area of fly ash, which leads to higher filler effect and improves the rate of cement hydration contributing to strength development. The comparison of strength of quartz-blended pastes and fly ash-blended pastes showed that the pozzolanic reaction of fly ash marginally contributes to strength development. The major influence of ground particles was seen on the region near to aggregates. Ground fly ash significantly increased the microhardness of interfacial transition zone near aggregates. Since this zone has a direct influence on the failure of mortars and concrete, its improvement resulted in a comparable strength of fly ash-blended mortars to the reference OPC mortar.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49488501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of temperature and clinker content on hydration and strength development of calcined clay blends","authors":"Arun C. Emmanuel, Shashank Bishnoi","doi":"10.1680/jadcr.21.00197","DOIUrl":"https://doi.org/10.1680/jadcr.21.00197","url":null,"abstract":"The effect of curing temperatures: 10°C, 27°C and 50°C, on hydration kinetics, phase assemblages and strength development of blends with calcined clay was investigated at two replacement levels. The temperature sensitivity of the blends significantly increased when the clinker is replaced with calcined clay, even at a 30% replacement level. The compressive strength development in calcined clay blends was higher than that of OPC at a lower temperature, perhaps due to formation of low-density products such as stratlingite, rather than enhanced clinker hydration. The reduced compressive strength development at 50°C for calcined clay blends could be due to multiple reasons such as lower clinker hydration, reduced pozzolanic reaction, and reduced stability of carboaluminates and ettringite. However, merely a 24-hour lag in this temperature exposure reverses this temperature effect, mainly due to the enhanced stability of carboaluminates and ettringite phases. It is seen that the reduction in hydration is mainly in the belite phase and could be due to the large changes in the C-A-S-H having a high alumina substitution. It is hypothesised that the adverse effect of high-temperature exposure in calcined clay blends is due to the formation of a physical barrier of highly polymerised C-S-H on the surface of the unhydrated clinker. The improved performance due to the delay in high-temperature exposure could be due to the enhanced stability of ettringite and carboaluminate phases.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49448885","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Early-age characterisation of Portland cement by impedance spectroscopy","authors":"Aldo F. Sosa Gallardo, J. Provis","doi":"10.1680/jadcr.21.00103","DOIUrl":"https://doi.org/10.1680/jadcr.21.00103","url":null,"abstract":"This paper applies alternating current impedance spectroscopy to assess the effect of different sand, anhydrite, and water contents on the electrochemical response of Portland cement in the early stages of hydration. Potential factors that may affect impedance measurements and data interpretation are also discussed, such as the complexity of cement chemical composition, its physical properties and hydration kinetics, and technique limitations. The impedance data obtained are benchmarked against different supporting techniques and literature data, showing a strong relationship among hydration rates as determined by thermochemistry, setting time measurements by physical approaches, pore fluid chemistry, electrical conductivity, and the impedance behaviour observed. The results demonstrate that ACIS is a sensitive technique to assess cement hydration, enabling differentiation of changes in the water and cement content, hydration degree, and microstructural development during the first 24 hours after mixing.","PeriodicalId":7299,"journal":{"name":"Advances in Cement Research","volume":" ","pages":""},"PeriodicalIF":2.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47804054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}